From 6aa2079079f6534359a2d24ac1641f986df3417a Mon Sep 17 00:00:00 2001
From: Alexandre Duret-Lutz <adl@lrde.epita.fr>
Date: Fri, 10 Sep 2021 11:47:44 +0200
Subject: [PATCH] zlktree: speedup the construction of ACD nodes

This uses the foreach_set_index() method introduced in the previous
patch to speed up the copy bitvectors in ACD nodes, as pointed in
issue #476.

Running
PREFIXCMD='valgrind --tool=callgrind' ./run python3 -c \
"import spot; spot.acd_transform(spot.automaton('syntcomp_91.hoa'))"
went from 65139436227 instruction fetches down to 18490399159.

* spot/twaalgos/zlktree.cc (acd::build_): Use foreach_set_index().
---
 spot/twaalgos/zlktree.cc | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/spot/twaalgos/zlktree.cc b/spot/twaalgos/zlktree.cc
index 6e9f32904..c86c929b5 100644
--- a/spot/twaalgos/zlktree.cc
+++ b/spot/twaalgos/zlktree.cc
@@ -482,12 +482,11 @@ namespace spot
           n.parent = node;
           n.level = lvl + 1;
           n.scc = scc;
-          for (unsigned e = 1; e < nedges; ++e)
-            if (bv->get(e))
-              {
-                n.edges[e] = true;
-                n.states[aut->edge_storage(e).src] = true;
-              }
+          bv->foreach_set_index([&](unsigned e)
+          {
+            n.edges[e] = true;
+            n.states[aut->edge_storage(e).src] = true;
+          });
         }
       unsigned after_size = nodes_.size();
       unsigned children = after_size - before_size;